We fit these with a sophisticated irradiated disc model and find that
this gives a self-consistent picture around the outburst peak. Weak
irradiation increases the inferred radius of the inner disc by a
factor \(\sim 1.5\) . Photons from the disc are the seeds for Compton
upscattering to produce the hard X-ray emission, and this hard X-ray
emission weakly illuminates the outer disc to produce the observed
optical/UV by reprocessing, as confirmed by the optical/X-ray
cross-correlation [1]}.
